Controlling means for automatic lathes



April 12, 1932. MUL

CONTROLLING MEANS FOR AUTOMATIC LATHES Filed Oct. 13, 1930 2Sheets-$heet III W April 12, 1932. F. MULKA CONTROLLING MEANS FORAUTOMATIC LATHES Filed Oct. 13, 1930 2 Sheets-Sheet 2 Patented Apr. 12,1932 UNITED STATES PATENT OFFICE CONTROLLING MEANS FOR- A'UTOM ATICLATHES Application filed October 13, 1930, Serial No. 488,469, and inGermany November 21, 1929.

Multiple-s indle automatic lathes are known, in w ich the controlling ofthe cross slides is effected by means of a reciprocating control ringarranged in the axis of the head stock.

A control has furthermore also been proposed in which all the automaticmovements are effected by a continuously revolving control drum coaxialwith the material spindle.

The present invention relates to a control which is particularlysuitable for automatic screw-cutting and profiling lathes. According tothe invention the controlling of all the automatic movements is effectedby means of two control rings arranged at t e front end of the headstock coaxially with the material spindle, of which one executes areciprocating movement, while the other revolves continuously. Thereciprocating ring eifects primarily the feeding movement of thecutting-removing tools, and therefore deserves the name of main controlring. The continuously revolving ring effects a positive to-and-frorotation of the main control ring and also executes the displacementswhich the main control ring, in consequence of its reciprocatingmovement, either cannot execute at all or can only executeinconveniently. The continuously revolving ring is therefore to beregarded as an auxiliary control ring.

The invention presents the following very important advantages forscrew-cutting and profiling lathes:

(1) The control by means of a reciprocating ring and a revolving rinenables all the parts t at occur to be pro need with constant curves inan equally advantageous manner.

(2) The adjustabilityof the machine is so improved that only a singlecam on the auxiliary control ring has to be ad usted 1n order to limitthe working and i le times for the mostrgvaried members.- (3) Theadjusting of the feeds for circularly swinging tools like that of thegripper and of the stop, is no longer necessary. The

alternately fast and slow running auxiliary control rin efiects apositive to-and-fro rotation of t e main control ring, which may takeplace partly fast and slow in both (11- rections of rotation. Thereversal of the direction of rotation of the main control ring iseifected after the termination of one working operation and before thecommencement of the ensuing operation. Now since after M the termination0f.one eriod of treatment the gripper must come 1nto action and beforethe commencement of the ensuing period the stop must be actuated, thealternating movements of the main control ring are utie0 lized for thesedisplacements.

(4) The superstructure of the lathe is considerably simplified, becausethe displacements of the displaceable tools and devices are executedwith a control ring located in 06 the working range, directly andwithout the assistance of transmission levers.

(5) The working spindle may be arranged obliquely in consequence of thenovel su rstructure of the lathe, as a result of w ich 7 an advantageousremoval of cuttings is obtained, and the forward feed can be efiected bymeans of the intrinsic weight of the bar of material.

.516) The controlling of a pluralit of cross 15 sli es by the maincontrol rmg, wit the employment of suitable turning processes enablescutting outputs to be obtained which are many times as great as those ofthe best known high-power machines.

The invention is illustrated by way of example in the accompanyingdrawings and is hereinafter described in detail.

Figure 1 shows a longitudinal section through an automatic screw-cuttingand proas filing lathe;

Figure 2 shows a section on the line 1-11 in Figure 1, and

Figure 3 shows a" view of the head stock from the front, certain partsbeing in section.. 1

Upon an inclined underf-rame 1 rests the head stock 2. A working spindle3 carries at its rear end a driving ulley 4. To the front end of thehead stoc is secured in a on known manner a cross-slide carrier 5. Uppnan extension 6 of the head stock is rotatad mountedthe main control ri'7, to WhlC is secured a. detachable earn 8. Upon the main control ringis rotatab y mounted loo an auxiliary control rin 9. The auxiliarycontrol ring 9 is rotate fast or slowly alternately by means of a wormwheel 10 and worm 11 in the direction of the arrow a in Figures 2 and 3.For the production of a workpiece one complete revolution of theauxillary control ring is required. The auxiliary control rin has on itsexternal surface cams 12 an 13, which serve for the displacement b knownmeans, not shown, of the clamping s eeve 14 of a clamping chuck 15 forthe material. A cam 16 on.the external cylindrical surface of theauxiliary control ring is adjustably arranged and serves for switchingon the slow rotation of the ring. The slow rotation of the auxiliarycontrol ring is effected during the machining of the work. e worm 11 isthen driven from the spindle by means of a worm 17, a worm wheel 18,change wheels 19 and 2,0, bevel wheels 22 and 23, a shaft 21, bevelwheels 22a and 23a, and a free-wheel coupling 24. The high speed of theworm 11 is obtained by switching on an electric motor 25 by means of anon-adjustable cam 26 on the main control ring. The free-wheel coupling24 then throws the slow drive of the bevel wheels 22a and 23a out ofaction,

as shown in Figure 3. The auxiliary control ring has also on itsexternal surface cams 27 and 28, of which the cam 27 is non-adjustablysecured, while the cam 28 is adjustably arranged. The non-adjustable cam27 acts against a roller 29 on a lever 30, which, by means of a toothedsegment 31, brings a circularly swinging lon lathe tool 32 into theworking position. he adjustable cam 28 serves for rocking back the longlathe tool, and in so doing acts against the roller 29 on the lever 30.The auxiliary control ring also serves the purpose of positively movinthe main control ring to and fro, this ing done in the following mannerThe movement of the main control ring in the direction of rotation ofthe auxiliary control ring, namely the direction shown by the arrow a inFigs. 2 and 3, is effected by a tappet pawl 33, which is rotatablymounted upon a bolt 34, owing to the fact that an abutment 35 secured tothe auxiliary control ring carries the pawl round with it. The movementof the main control ring in the direction of the arrow a is terminatedwhen a roller 36 on the tappet pawl runs up an inclined surface on an astop 35; Before this releasing of the tappet pawl is effected a toothedsegment 38 sup- ,ported in the main control ring runs against af'stop 39secured to the extension 6. Since utment 37 secured to the extension .6,and in sodoing releases the pawl from the The toothed segment 38 remainspermanently in engagement with a pinion 41. The latter 1s mounted uponits pivot 42 (Fig. 1) in the head stock. If, as described above, thetoothed segment 38 has run against the stop 39, the pinion remains in adefinite position of rest until internal teeth 43 provided in theauxiliary control ring come into engagement. This engagement alwaystakes place normally because the position of rest of the pinion isalways the same when the toothed segment 38 is pressed against the stop39. Upon the entrance of the internal teeth 43 into the pinion 41 arotation of the toothed segment 38 takes place in the direction of thearrow 6 in Figure 2, while the main control ring is still being moved inthe direction of the arrow a. The toothed segment 38 then moves awayfrom the stop 39 and compresses the sprin 40 still further. At the sametime the rol er 36 of the tappet pawl 33 passes on to the inclinedsurface of the stop 37 and releases the tappet pawl from the stop 35 inthe auxiliary control ring. The rotation of the main control ring in thedirection of the arrow a therefore ceases, and the main control ring isnow carried round in the direction of the arrow 6 b the toothed segment38 until the internal teeth 43 become disengaged from the pinion 41.Thereupon the main control ring stops in a position of rest until theauxiliary control ring continuing to revolve in the direction of thearrow a takes it round again in the direction of the arrow a with itsstop 35. In order to ensure the tappet pawl reliably snapping in, aspring 44 presses the abutment end of the pawl against the internalsurface of the auxiliary control ring.

The movement of the main control ring in the direction of the arrow 6 iseffected constantly at the high speed, after the immovable cam 26 hasswitched on the high speed of the auxiliary control ring. The auxiliarycontrol ring also takes the main control ring with it in the directionof the arrow a at the high speed, and through a variable distance, whichis limited by the adjustable cam 16.

Since the object of the auxiliary control ring has now been explained, adetailed descrlption of the cam ring 8 mounted on the main control ringwill now be given.

The cam ring 8 has four parting cams 45, which impart the feedingmovement to the four cross slides 46. The rise of the cams correspondsto the maximum parting depth.

When the main control ring changes the direction of rotation into thedirection of the arrow (1, the parting cams have always arrived withtheir highest points 45a upon supporting rollers 47 A roller-holder 48is slidably supported in the cross slides for the purpose ofcompensating for differences of diameter in the workpieces to bemachined. Upon the pivot 49 is rotatably mounted a spring gripper 52,this member is a known 1 element in automatic lathes, the duty of whichis to receive the finished piece of work falling oil from the stock rod,for the purpose of depositing it in a suitable position or delivering itto some supplementary apparatus, for instance a slotting saw for thepurpose of cutting a slot in a screw head. Before the cams 45 havearrived upon their point 4511, a toothed segment 53 passes into a pinion54 connected with the gripper and rocks the gripper towards the centrepoint of the workpiece. Upon reversal of the direction of rotation ofthe main control ring the gripper is rocked back and the cross slide isreturned. Upon the termination of the rotation of the main control ringin the direction of the arrow b a toothed segment 55 enters into a inion56 serving to actuate the stop and roc s a stop arm 57, which is mountedupon a carrying pivot, into the working position. The stop thereuponremains in a position of rest with the main control ring until theauxiliary control ring, continuing to revolve, has ef fected thegripping of the rod of material that has been fed forward, and carriesthe main'control ring round again in the direction of the arrow (1. Byrotating the main control ring in the direction a the stop is rockedbackwards.

Upon the carrying pivot 51 is mounted the long swinging lathe toolholder 32, carrying a tool 32a. With the rocking back of the stop therocking in of the long lathe tool holder is commenced by means of thecam 27. An outward extension 59 of the long lathe tool holder'moves in acircumferential groove in a slider 60. The slider 60 is movedlongitudinally by a. helical cam 61, the side of the said cambearingagainst the roller 60a of the slider and thereby effecting theforward feed of the long lathe tool holder. The tool 32a is onlyintended to serve for the smooth-turns ing or finishing of therough-turned workpiece. The rough turning is always done by the turningtools 66. The securing of the tool 32a in the oscillating arm 32 may beefl'ected in any convenient manner, for instance the lathe tool 32a maybe inserted in a bore in the oscillating arm 32, and secured therein bymeans of a clamping screw. A

; screw thread cutting tool 62 is moved longitudinally by a cam 63, bymeans of a slider 64, a roller 64a and a toothed wheel 65 (Fig. 1) inthe same manner as the long lathetool holder. The rollers 60a and 64aare so supported as to be axially displaceable and rotatable, in orderthat during the backward rotation of the main control ring in thedirection of they arrow b the inclined surfaces 61a and 63a ofthe backsof the cams may be able to press the rollers back,

Some ofthe cams employed on'this automatic lathe are made adjustable, ina man ner well known and extensively employed in automatic machinetools. For instance it will be seen from Figure 1 that the cam 63 isclamped to theconvex surface of the control ring 8 by means of boltsscrewed into dovetail-shaped nuts which are slidable inan annular groovein the control ring. In other instances the means by which the cams aremade adjustable have been omitted from the drawings in order to simplifythe latter.

The invention may be applied within wide limits to automatic lathes.Thus according to the invention this control may also be employed in thecase of semi-automatic lathes, and also in the case of multiple-s indleautomatics. Then again instead 0 the screw thread cutting tool arevolving slide or a loose head stock or a simple longitudinal saddlemay be employed. Instead of four cross slides. only three or even twomay be provided. Furthermore the to-and-fro rotation of the main controlring may be effected in a manner different from that hereinbeforedescribed, for instance the pinion 41 might be constructed as a frictionroller in order that the internal teeth 43 and the teeth of the toothedsegment 38 may be omitted, without thereby going outside the scope ofthe invention.

WVhat I claim is 1. Controlling means for automatic and semiautomaticlathes, comprising a head stock, an outer control ring rotatably mountedat the front end of the head stock, means for rotating the outer controlring continuously in one direction at two different speeds alternately,a main control ring supported co-axially in the outer control ring, andtransmission means by which the continuously revolving outer controlring imparts a to-and-fro rotation to the main control ring.

2. Controlling means for automatic and semiauomatic lathes as claimed inclaim 1, the said transmission means comprising a tappet pawl pivotallymounted in the main control ring, and an internal abutment on the outercontrol ring ada ted to engage with the said tappet pawl an thereby toconstrain the main control ring torotate with the outer control ring.

3. Controlling means for automatic and semiautomatic lathes as claimedin claim 1, the said transmission means comprising a row of teethextending a certain distance round the internal periphery of the outercontrol ring, a pinion journalled in the head stock and capable ofmeshing with the said row of teeth, and an externally toothed segment onthe main control ring permanently with the said pinion. 4. Controllingmeans for automatic and semiautomatic lathes as claimed in claim 1,

the said transmission means comprising a stock and capable of meshingwith the said meshing row of teeth, an externally toothed se entrotatably mounted on the main contro ring and permanently meshin withthe said pinion, a stop secured to t head stock and adapted to limit themovement of the externally toothed segment in one direction, and aspring tending to press the externally toothed segment against the stop.

5. Controlling means for automatic and semiautomatic lathes, comprisinga head stock, four cross slides, an outer control ring rotatably mountedat the front end of the head stock, means for rotating the outer controlring continuously in one direction at two different speeds alternately,a main control rin supported co a'xially in the outer contro ring,transmission means by which the continuously revolving outer controlring imparts a to-rand-fro rotation to the main control ring, a cam ringdetachably secured to the main control ring, and four cams ninetydegrees apart on the said camring, the said cams being adapted to actcollectlvely, in a plane perpendicular to the axis of rotation, upon therear ends of the cross slides and thereby to impart a feeding movementto the cross slides.

6. Controlling means for automatic and semiautomatic lathes as claimedin claim 5, further comprisingla circularly swinging gripper, a toothedsegment secured to the face of the cam ring, gear teeth on the gripper,a p nion meshing with the gear teeth on the gripper and adapted to beengaged and rotated by the toothed segment on the cam ring and therebyto rock the gripper inwards a short time before the termination of thefeedingfnovement of the cross slides and to rock the gripper outwardsagain when the. direction of rotation of the main control ring and thecam ring is reversed.

7. Controlling means for automatic and actuated by the said cam to rockthe lon lathe tool holder inwards during the outward rocln'ng movementof the abutment arm,' an adjustable cam mounted on the outer controlring and adapted to rock the long lathe tool holder outwards, and acircumferential cam secured to the cam ring and adapted to effect theforward feed of the inwardly rocked long lathe tool holder.

9. Controlling means for automatic and semiautomatic lathes, comprisinga head stock, a clamping chuck for the material to be machined, an outercontrol rin rotatably mounted at the front end of the head stock, meansfor rotating the outer control ring continuously in one direction at twodifferent speeds alternately, a main control rin supported co-axially inthe outer contro ring, transmission means by which the continuouslyrevolving .outer control ring imparts a to-and-fro rotation to the maincontrol ring, leaving it stationary for a short interval between itsmovements in opposite directions, and cams secured to the outer controlring. the same cams being adapted to open and close the chuck during theintervals between the rotation of the main control ring in oppositedirections.

In testimony whereof I have signed my name to this specification.

FRIEDRICH MULKA.

sem automatic lathes as claimed in claim 1, 3

further comprising a circularly swinging abutment arm, means for rockingthe abutment arm inwards a short time before the i termination of thereversed rotation of the main control ring, and means for rocking theabutment arm outwards while the main control ring is being carried roundby the outer control r ng in its own direction of rotation.

'tool holder, a non-adjustable cam secured'to I 1 the outer controlring, means adapted to be 8. Controlling means for automatic andsemiautomatic lathes as claimed in claim 1,

secured to the main control ring, a circularly rotation, a circularlyswinging'long lathe

